A keratin vitamin is a supplement taken that supports healthy skin, hair and nails. It is difficult to get all the vitamins needed through diet, and taking a supplement can help.
Vitamins are substances that are either made by the body or provided through food. Experts agree they are essential for health and normal development. Keratin is not a vitamin, but a natural body protein responsible for nourishment and repair. To support natural keratin production, the USDA recommends eating foods rich in iron and lean protein.
Taking keratin vitamins to promote hair growth is common and can be helpful or harmful, depending on the quality of the product. According to the American Academy of Dermatology, not all products are scientifically based, and many pose negative, long-term effects. Numerous manufacturers receive citations from OSHA each year or are completely banned from producing certain products.
For the body to make the keratin it needs to function, the Institute of Medicine recommends that 10 to 35 percent of daily calories come from protein, and adequate amounts of vitamins A and D should also be consumed. Some experts agree that consumers should be cautious and consult a medical professional before purchasing or using a keratin supplement.